The Green Bay Packers are dead serious about giving first-round pick Derek Sherrod every chance to win the starting left guard job even though the last time he played the positions was …

“Ah, never,” the rookie said Sunday.

In a sign that it’s much more than just an early training camp experiment, Packers coach Mike McCarthy gave Sherrod a second straight day of work with the starters at his new position. Sherrod somewhat surprisingly opened camp on Saturday night as the starting left guard.

The Packers could have gone with veteran T.J. Lang (a fourth-round pick in 2009) – and Lang may still get his chance – but they are banking on Sherrod’s talent and smarts (he had a 3.5 grade point average at Mississippi State) that he can make the adjustment even though the lockout robbed him of any prep time before camp.

That’s not to say the job has been handed to Sherrod, but if he is to have a realistic chance to compete once the pads go for the first time on Monday night, then he probably needed these two days of non-padded work with the starters to get comfortable.

It appears Sherrod and Lang are the only two contenders to replace Daryn Colledge, a starter for most of the last five seasons before he left for the Arizona Cardinals in free agency last week. The other possible contender, second-year pro Nick McDonald, has worked exclusively at center behind starter Scott Wells in the early going.

McCarthy needs to find out soon whether Sherrod can make the shift from tackle, where he played exclusively at Mississippi State and in high school. The 6-foot-5 Sherrod has a body type more suited to tackle, but the Packers like athletic guards to run their zone blocking scheme, and Sherrod moves well. He weighed 321 pounds at the combine in February but said he weighed in on Friday at 312.

“It’s not too much different than tackle,” Sherrod said. “You still have to know all the positions anyway. It’s just changing up a little bit of technique.”

In some ways, playing guard for the Packers carries more responsibility. Their pass protection is designed to block inside out, meaning the protection calls start with the interior linemen.

McCarthy has never been shy about moving around linemen. Last August, he gave rookie first-round pick Bryan Bulaga a shot to compete with Colledge at left guard before moving Bulaga back to right tackle, where he eventually replaced Mark Tauscher later in the year. Even Colledge was moved around earlier in his career, splitting time between left guard and left tackle.

McCarthy called Sherrod’s performance the first day “OK” after viewing the film on Sunday morning.

“The first time out there playing guard, a lot of information, a lot of communication going on, just being able to play at that speed is going to take some time, and it’s going to take reps,” McCarthy said. “The positive is he gets to go against a defense that’s going to throw everything at you so that by the time we go through three installs, the competition as far as how he’s challenged up front schematically, he’ll pretty much have seen it all. It’s great work for him. I like what I saw physically.”

The Packers drafted Sherrod to be one of the tackles of the future – either on the left side when veteran Chad Clifton wears out or on the right side if Bulaga moves to left – but they aren’t averse to playing him at guard, even if it’s only for a year.

“We’re really going to have to find somebody, either Derek or T.J., (and) figure out what we’re going to do over there to make sure that we have a guy who’s mentally sharp because our offense is so diverse in what we’re trying to do,” quarterback Aaron Rodgers said. “We can do a lot of things at the line of scrimmage if we want to. There’s a lot of different calls.

"(Sherrod)’s a guy who played tackle last year, and he’s going to have to quickly understand how to play guard in this offense. I think the talent is there, the big body is there, but he needs to get to the point where he’s not thinking as much, and it’s going to take some time. But I think we’re all very optimistic about his future.”

Meanwhile, Lang will have to wait for his chance.

Last summer, he never got one because a wrist injury took away his entire offseason and then slowed him at the start of camp. He broke a bone in his left wrist late in his rookie season, but it wasn’t discovered that surgery was needed until he returned for the offseason program the next March. He still wears a brace on the wrist, but it hasn’t given him any trouble in months.

Lang spent the lockout working out with teammates Frank Zombo and McDonald at Dynamic Athlete Performance in Canton, Mich. The 6-4 Lang said his weight is about the same as last year, between 315 and 320 pounds (he’s listed at 318), but says he’s in the best shape of his pro career. Knowing it was likely that Colledge would depart in free agency, Lang spent the offseason preparing for his shot at a starting job. When or if that opportunity will come remains to be seen.

Lang said he wasn’t disappointed that Sherrod got the first shot. If nothing else, it intensified his desire to compete.

“I certainly didn’t think it was going to be handed to me,” Lang said. “I’m glad to be in the position I’m in. I’m going to have to fight for a spot. They’re going to try to make me earn it. That’s good. It’s going to me a better player competing with those guys. I’m definitely not getting down on the fact that I was with the twos, but it’s definitely going to make me work that much harder.”

Regardless of what happened the first days of camp, the more important tests will come when in the padded practices and during the preseason games. That’s where Lang’s experience, though limited to backup duty in his two pro seasons, might give him an edge.

“That’s how we’re graded, how we play in pads,” Lang said. “So I think that’s going to help me when I can get in there and pop some pads.”

McDonald could work his way into the left guard picture, but the Packers prefer a two-man competition on the line because of the limited reps to go around.